| transgenic analysis of a hybrid poplar wound-inducible promoter reveals developmental patterns of expression similar to that of storage protein genes. | the wound-inducible win3 multigene family from hybrid poplars (populus trichocarpa x populus deltoides) encodes proteins with structural similarities with kunitz-type protease inhibitors (h.d. bradshaw jr., j.b. hollick, t.j. parsons, h.r.g. clarke, m.p. gordon [1990] plant mol biol 14: 51-59), and at least one member, win3.12, is transcribed de novo in the injured and uninjured leaves of wounded trees (j.b. hollick, m.p. gordon [1993] plant mol biol 22: 561-572). a previous study demonstrated t ... | 1995 | 7480333 |
| expression of poplar phenylalanine ammonia-lyase in insect cell cultures. | a cdna encoding one of the phenylalanine ammonia-lyase genes from populus trichocarpa x deltoides was inserted into a baculovirus expression vector and the pal protein was successfully expressed in insect cell cultures. high levels of active holoenzyme were obtained that could be purified in a single chromatographic step. site-directed mutagenesis and expression of the mutant enzyme confirmed that conversion of the putative active site serine202 residue to alanine is sufficient to destroy the ca ... | 1996 | 8729456 |
| 4-coumarate:coenzyme a ligase in hybrid poplar. properties of native enzymes, cdna cloning, and analysis of recombinant enzymes. | the enzyme 4-coumarate:coenzyme a ligase (4cl) is important in providing activated thioester substrates for phenylpropanoid natural product biosynthesis. we tested different hybrid poplar (populus trichocarpa x populus deltoides) tissues for the presence of 4cl isoforms by fast-protein liquid chromatography and detected a minimum of three 4cl isoforms. these isoforms shared similar hydroxycinnamic acid substrate-utilization profiles and were all inactive against sinapic acid, but instability of ... | 1998 | 9489021 |
| rapid alkalinization factors in poplar cell cultures. peptide isolation, cdna cloning, and differential expression in leaves and methyl jasmonate-treated cells. | a family of peptides inducing rapid ph alkalinization in hybrid poplar (populus trichocarpa x populus deltoides) cell culture medium was isolated from hybrid poplar leaves. five related approximately 5-kd peptides were purified by high-performance liquid chromatography and analyzed by matrix-assisted laser desorption ionization-mass spectrometry. the n-terminal sequence of one of the isolated peptides was very similar to a previously characterized peptide from tobacco (nicotiana tabacum), rapid ... | 2003 | 12586905 |
| poplar metal tolerance protein 1 confers zinc tolerance and is an oligomeric vacuolar zinc transporter with an essential leucine zipper motif. | cation diffusion facilitator (cdf) proteins are a recently discovered family of cation efflux transporters that might play an essential role in metal homeostasis and tolerance. here, we describe the identification, characterization, and localization of ptdmtp1, a member of the cdf family from the hybrid poplar populus trichocarpa x populus deltoides. ptdmtp1 is expressed constitutively and ubiquitously, although at low levels. heterologous expression in yeast showed that ptdmtp1 was able to comp ... | 2003 | 14630973 |
| defining hybrid poplar (populus deltoides x populus trichocarpa) tolerance to ozone: identifying key parameters. | this study examined whether two genotypes of hybrid poplar (populus deltoides x populus trichocarpa), previously classified as ozone tolerant and ozone sensitive, had differing physiological and biochemical responses when fumigated with 120 nl l(-1) ozone for 6 h per day for eight consecutive days. isoprene emission rate, ozone uptake and a number of physiological and biochemical parameters were investigated before, during and after fumigation with ozone. previous studies have shown that isopren ... | 2009 | 19076530 |
| linking irradiance-induced changes in pit membrane ultrastructure with xylem vulnerability to cavitation. | the effect of shading on xylem hydraulic traits and xylem anatomy was studied in hybrid poplar (populus trichocarpa x deltoides, clone h11-11). hydraulic measurements conducted on stem segments of 3-month-old saplings grown in shaded (sh) or control light (c) conditions indicated that shading resulted in more vulnerable and less efficient xylem. air is thought to enter vessels through pores in inter-vessel pit membranes, thereby nucleating cavitation. therefore, we tested if the ultrastructure a ... | 2010 | 21118422 |
| habituation to thaxtomin a in hybrid poplar cell suspensions provides enhanced and durable resistance to inhibitors of cellulose synthesis. | thaxtomin a (ta), a phytotoxin produced by the phytopathogen streptomyces scabies, is essential for the development of potato common scab disease. ta inhibits cellulose synthesis but its actual mode of action is unknown. addition of ta to hybrid poplar (populus trichocarpa x populus deltoides) cell suspensions can activate a cellular program leading to cell death. in contrast, it is possible to habituate hybrid poplar cell cultures to grow in the presence of ta levels that would normally induce ... | 2010 | 21143977 |
| influence of evaporative demand on aquaporin expression and root hydraulics of hybrid poplar. | we measured aquaporin expression and root hydraulic conductance of hybrid poplar plants subjected to different levels of light. shade-grown saplings experiencing a sudden increase in light exhibited a three-fold higher root hydraulic conductance than plants remaining in shade. this dynamic increase corresponded with increased transcript abundance of 15 aquaporin genes out of a total of 33 genes simultaneously assessed by quantitative rt-pcr. | 2011 | 21477124 |
| ftir-atr-based prediction and modelling of lignin and energy contents reveals independent intra-specific variation of these traits in bioenergy poplars. | abstract: | 2011 | 21477346 |
| maturation stress generation in poplar tension wood studied by synchrotron radiation microdiffraction. | tension wood is widespread in the organs of woody plants. during its formation, it generates a large tensile mechanical stress, called maturation stress. maturation stress performs essential biomechanical functions such as optimizing the mechanical resistance of the stem, performing adaptive movements, and ensuring long-term stability of growing plants. although various hypotheses have recently been proposed, the mechanism generating maturation stress is not yet fully understood. in order to dis ... | 2010 | 20071605 |
| increased leaf area expansion of hybrid poplar in elevated co2. from controlled environments to open-top chambers and to face. | we examined the response of hybrid poplar to elevated co2 in contrasting growth environments: controlled environment chamber (ce). open-top chamber (otc) and poplar free air co2 enrichment (popface) in order to compare short versus long-term effects and to determine whether generalisations in response are possible for this fast growing tree. leaf growth, which for poplar is an important determinant of stemwood productivity was followed in all environments, as were the determinants of leaf growth ... | 2001 | 11789926 |
| maturation stress generation in poplar tension wood studied by synchrotron radiation microdiffraction. | tension wood is widespread in the organs of woody plants. during its formation, it generates a large tensile mechanical stress called maturation stress. maturation stress performs essential biomechanical functions such as optimizing the mechanical resistance of the stem, performing adaptive movements, and ensuring the long-term stability of growing plants. although various hypotheses have recently been proposed, the mechanism generating maturation stress is not yet fully understood. in order to ... | 2010 | 21068364 |
| transcriptome profiles of hybrid poplar (populus trichocarpa × deltoides) reveal rapid changes in undamaged, systemic sink leaves after simulated feeding by forest tent caterpillar (malacosoma disstria). | • poplar has been established as a model tree system for genomic research of the response to biotic stresses. this study describes a series of induced transcriptome changes and the associated physiological characterization of local and systemic responses in hybrid poplar (populus trichocarpa × deltoides) after simulated herbivory. • responses were measured in local source (lso), systemic source (sso), and systemic sink (ssi) leaves following application of forest tent caterpillar (malacosoma dis ... | 2010 | 20955416 |
| components acting downstream of short day perception regulate differential cessation of cambial activity and associated responses in early and late clones of hybrid poplar. | short days (sds) in autumn induce growth cessation, bud set, cold acclimation, and dormancy in trees of boreal and temperate forests, and these responses occur earlier in northern than in southern genotypes. nevertheless, we know little about whether this variation results from differential perception of sds or differential downstream responses to the sd signal or a combination of the two. we compared global patterns of sd-regulated gene expression in the stems of hybrid poplar (populus trichoca ... | 2010 | 20847139 |
| extensive allelic variation in gene expression in populus f1 hybrids. | hybridization between plant species can induce speciation as well as phenotypic novelty and heterosis. hybrids also can show genome rearrangements and gene expression changes compared with their parents. here we determined the allelic variation in gene expression in populus trichocarpa x populus deltoides f(1) hybrids. among 30 genes analyzed in four independently formed hybrids, 17 showed >1.5-fold expression biases for one of the two alleles, and there was monoallelic expression of one gene. e ... | 2007 | 18073418 |
| functional analysis of the kunitz trypsin inhibitor family in poplar reveals biochemical diversity and multiplicity in defense against herbivores. | we investigated the functional and biochemical variability of kunitz trypsin inhibitor (kti) genes of populus trichocarpa x populus deltoides. phylogenetic analysis, expressed sequence tag databases, and western-blot analysis confirmed that these genes belong to a large and diverse gene family with complex expression patterns. five wound- and herbivore-induced genes representing the diversity of the kti gene family were selected for functional analysis and shown to produce active kti proteins in ... | 2008 | 18024557 |
| transcript profiling of poplar leaves upon infection with compatible and incompatible strains of the foliar rust melampsora larici-populina. | to understand key processes governing defense mechanisms in poplar (populus spp.) upon infection with the rust fungus melampsora larici-populina, we used combined histological and molecular techniques to describe the infection of populus trichocarpa x populus deltoides 'beaupré' leaves by compatible and incompatible fungal strains. striking differences in host-tissue infection were observed after 48-h postinoculation (hpi) between compatible and incompatible interactions. no reactive oxygen spec ... | 2007 | 17400708 |
| activation of stress-responsive mitogen-activated protein kinase pathways in hybrid poplar (populus trichocarpa x populus deltoides). | plant mitogen-activated protein kinase (mapk) cascades are important amplifying modules that can rapidly transduce stress signals into various appropriate intracellular responses. several extracellular regulated kinase (erk)-type mapks involved in plant defense signaling have been identified in herbaceous species, but no mapk cascade has yet been characterized in a tree species. we examined the signal transduction events that lead to activation of defense mechanisms in poplar, a major forest spe ... | 2005 | 15631976 |
| cloning, functional expression, and subcellular localization of multiple nadph-cytochrome p450 reductases from hybrid poplar. | nadph:cytochrome p450 reductase (cpr) provides reducing equivalents to diverse cytochrome p450 monooxygenases. we isolated cdnas for three cpr genes (cpr1, cpr2, and cpr3) from hybrid poplar (populus trichocarpa x populus deltoides). deduced cpr2 and cpr3 amino acid sequences were 91% identical, but encoded isoforms divergent from cpr1 (72% identity). cpr1 and cpr2 were co-expressed together with the p450 enzyme cinnamate-4-hydroxylase (c4h) in yeast (saccharomyces cerevisiae). microsomes isolat ... | 2002 | 12481067 |
| functional characterization and subcellular localization of poplar (populus trichocarpa x populus deltoides) cinnamate 4-hydroxylase. | cinnamic acid 4-hydroxylase (c4h), a member of the cytochrome p450 monooxygenase superfamily, plays a central role in phenylpropanoid metabolism and lignin biosynthesis and possibly anchors a phenylpropanoid enzyme complex to the endoplasmic reticulum (er). a full-length cdna encoding c4h was isolated from a hybrid poplar (populus trichocarpa x p. deltoides) young leaf cdna library. rna-blot analysis detected c4h transcripts in all organs tested, but the gene was most highly expressed in develop ... | 2001 | 11351095 |
| polyphenol oxidase from hybrid poplar. cloning and expression in response to wounding and herbivory. | the inducible expression of polyphenol oxidase (ppo), a presumed antiherbivore enzyme, was examined in hybrid poplar (populus trichocarpa x populus deltoides). following mechanical wounding simulating insect damage, ppo activity increased dramatically in wounded and unwounded leaves on wounded plants beginning at 24 and 48 h, respectively. a hybrid poplar ppo cdna was isolated and its nucleotide sequence determined. on northern blots, ppo transcripts were detected within 8 h of wounding, and rea ... | 2000 | 10982443 |
| structure, inheritance, and expression of hybrid poplar (populus trichocarpa x populus deltoides) phenylalanine ammonia-lyase genes. | a heterologous probe encoding phenylalanine ammonia-lyase (pal) was used to identify pal clones in cdna libraries made with rna from young leaf tissue of two populus deltoides x p. trichocarpa f1 hybrid clones. sequence analysis of a 2.4-kb cdna confirmed its identity as a full-length pal clone. the predicted amino acid sequence is conserved in comparison with that of pal genes from several other plants. southern blot analysis of popular genomic dna from parental and hybrid individuals, restrict ... | 1993 | 8108506 |
| Phytotoxicity testing of lysimeter leachates from aided phytostabilized Cu-contaminated soils using duckweed (Lemna minor L.). | Aided phytostabilization of a Cu-contaminated soil was conducted at a wood preservation site located in southwest France using outdoor lysimeters to study leaching from the root zone and leachate ecotoxicity. The effects of Cu-tolerant plants (Agrostis gigantea L. and Populus trichocarpa x deltoides cv. Beaupré) and four amendments were investigated with seven treatments: untreated soil without plants (UNT) and with plants (PHYTO), and planted soils amended with compost (OM, 5% per air-dried soi ... | 2011 | 22000292 |
| tree-based intercropping systems increase growth and nutrient status of hybrid poplar: a case study from two northeastern american experiments. | tree-based intercropping is considered to be a potentially useful land use system for mitigating negative environmental impacts from intensive agriculture such as nutrient leaching and greenhouse gas emissions. rapid early growth of trees is critical for rapidly accruing environmental benefits provided by the trees. we tested the hypothesis that intercropping increases the growth and nutrient status of young hybrid poplars (populus spp.), compared to a harrowing alley treatment (i.e., no intercr ... | 2009 | 19783353 |
| productivity, water-use efficiency and tolerance to moderate water deficit correlate in 33 poplar genotypes from a populus deltoides x populus trichocarpa f1 progeny. | genotypic variability for productivity, water-use efficiency and leaf traits in 33 genotypes selected from an f1 progeny of populus deltoides bartr. ex marsh x populus trichocarpa l. was explored under optimal and moderate water-deficit conditions. saplings of the 33 genotypes were grown in a two-plot open field at inra orléans (france) and coppiced every year. a moderate water deficit was induced during two successive years on one plot by withholding irrigation, while the second one remained ir ... | 2009 | 19773340 |
| analysis of the poplar phloem proteome and its response to leaf wounding. | phloem exudate collected from hybrid poplar (populus trichocarpa x populus deltoides) was estimated to have more than 100 proteins, of which 48 were identified using lc-ms/ms. comparative two-dimensional gel electrophoresis demonstrated that two phloem exudate proteins were significantly (p<0.05) upregulated 24 h after leaf wounding. these were identified as pop3/sp1 and a thaumatin-like protein. this is the first characterization of a phloem proteome from a tree species. | 2009 | 19245218 |
| microgenomic analysis reveals cell type-specific gene expression patterns between ray and fusiform initials within the cambial meristem of populus. | the vascular cambium is the meristem in trees that produce wood. this meristem consists of two types of neighbouring initials: fusiform cambial cells (fccs), which give rise to the axial cell system (i.e. fibres and vessel elements), and ray cambial cells (rccs), which give rise to rays. there is little molecular information on the mechanisms whereby the differing characteristics of these neighbouring cells are maintained. a microgenomic approach was adopted in which the transcriptomes of fccs a ... | 2008 | 18631289 |
| forest tent caterpillars (malacosoma disstria) induce local and systemic diurnal emissions of terpenoid volatiles in hybrid poplar (populus trichocarpa x deltoides): cdna cloning, functional characterization, and patterns of gene expression of (-)-germacrene d synthase, ptdtps1. | feeding forest tent caterpillars (ftcs) induced local and systemic diurnal emissions of (-)-germacrene d, along with (e)-beta-ocimene, linalool, (e)-4,8-dimethyl-1,3,7-nonatriene (dmnt), benzene cyanide, and (e,e)-alpha-farnesene, from leaves of hybrid poplar. ftc feeding induced substantially higher levels of volatiles in local and systemic leaves than did mechanical wounding. a full-length poplar sesquiterpene synthase cdna (ptdtps1) was isolated and functionally identified as (-)-germacrene d ... | 2004 | 14756770 |